Kivy using raspberry pi 3

I'm using the HDMI output of Raspberry Pi 3 . Using a Python code that opens a Kivy window, this window fills the entire screen and overrides everything else (open windows, mouse pointer ). ..). Apparently it ( rasp ) responds to the commands as it is possible to hang up, but in the window you can not do anything. How can I correct it by using it normally?

import kivy 
kivy.require('1.0.6') 
from kivy.app import App 
from kivy.uix.label import Label 
class MyApp(App): 
   def build(self):
      return Label(text='Hello world') 
if name == 'main':
   MyApp().run()